I’ve worked through this is quite a bit of detail. I have found it hard to understand everything but I think I have enough of an idea to give you some pointers.
First I think that it can be simplified quite a bit.
The first things I did was clean up the model and added a Comptes index table.
You want this because you need to be able to filter both your actuals and budgets table at the same time. In you prepared model you couldn’t do that because your slicer was coming from the Comptes table itself and there was no relationship with the budget table.
I used a simple VALUES function as a calculated table to create this.
Now the slicer inside your report should come from this table
One things I don’t really understand is why so many formulas here
I’m not sure why these would be required. Can’t you get similar calculations with just a simple sum of the columns.
Maybe the new model setup will help you here.
I’m pretty confident you don’t need many of the DAX measures that have been create. Most of the calculations can be created with just the right model setup and then correct filters and slicer within your report page.
I’ve added the attached model here to continue working on.
Let me know if any questions from here.
I’m not sure if I’ve answered your question specifically but this is where I can get to without more information required around what you’re looking to achieve. Hopefully this give you some ideas to work on though